WADA Yuji was a meteorologist who played a role in the colonial era of Korea. The Investigation Report by WADA published in 1917 is well known as the most important study on the history of Korean meteorology, though it has not been discussed in detail until today.In this paper, the monographs for the rain gauge that is so called 'Choogugi' and the measuring records of the rainfall depth in the Report are considered and evaluated in terms of the Cultural Imperialism.